This invention is in the field of computer displays and methods for their manufacture. Specifically, a first embodiment of the present invention relates to a liquid crystal display ("LCD") and a method for its assembly.
LCDs are commonly used in portable computers, calculators and other small, microprocessor controlled devices for the display of data and graphics generated by the devices to which they are coupled. These displays are known in the industry and generally function adequately.
Although known LCDs are adequate to their tasks, they share some common problems. Known displays are generally thicker than desired, a result of a complicated method of construction. The same defects in the construction process result in an LCD assembly that is not as strong as desired. Given that the display qualities of an LCD panel can be seriously affected by twisting the panel, the lack of strength in known panels is a serious problem. Finally, the complexity of the construction process increases the cost of the assembled panel.
FIGS. 1 through 4 show how a known LCD panel is constructed. FIG. 1 is an exploded isometric drawing of the panel's backlighting system. Backlighting assembly 10 centers around backlighting panel 11, which distributes the light generated by fluorescent light fixture 19 across the entire LCD panel. Backlighting panel 11 is set into plastic end pieces 13 and 14. Mounting flanges in pieces 13 and 14 hold panel 11 in proper alignment. Fluorescent light fixture 19 is placed in end piece 13, abutting backlighting panel 11. Backlighting assembly 10 is held together by metal frame pieces 16, 17, and 18 which overlap the edges of panel 11. Frame piece 17 is shaped to accommodate fixture 19. When frame pieces 16,17, and 18 are screwed to plastic end pieces 13 and 14 using screws 12, assembly 10 is held together as a single unit. FIG. 1a details how light fixture 19, end piece 13, and backlighting panel 11 are held together by metal frame pieces 17 and 18.
FIG. 2 is an exploded isometric drawing showing how LCD panel 20, with its supporting electronics, is mounted atop backlighting assembly 10. Hole 21 in LCD panel 20 aligns with peg 22 on assembly 10 and insures proper alignment of panel 20 with backlighting assembly 10. This alignment feature is shown in detail in FIG. 2a.
FIG. 3 is an exploded isometric drawing showing how metal frame 30 is mounted over the backlighting assembly 10 and LCD panel 20 combination. Not shown are several strips of gasket material which are placed between the LCD panel and the metal frame to protect the panel from damage. Tabs 31 on frame 30 are crimped against the LCD panel/backlighting assembly to form a single unit. This finished unit is shown in FIG. 4.
The unit shown in FIG. 4 is, unfortunately, not ready for use in a portable computer or other computer-based system. Typically it is mounted in a plastic casing having a front bezel and a rear back piece. The plastic casing can be held together in any one of several ways, including screws and plastic rivets. Only after the assembly shown in FIG. 4 has been mounted in such a casing can it be used in a portable computer system. To reduce or eliminate electromagnetic interference ("EMI"), EMI shields may be needed. These shields, which typically comprise a thin sheet plastic coated with an electrical conductor, would encapsulate the finished module and would fit between the module and its plastic casing.
Although the display manufacturing process and the finished display shown in FIGS. 1 through 4 is acceptable, it is also complex, has many parts, and still requires further assembly before it can be used in an actual computer system. In particular, the metal frame and the plastic case are somewhat redundant. A simpler assembly process, requiring fewer parts to produce a usable LCD would be very desirable.